1. Field of the Invention
This invention relates to a film number writing system and more particularly to a system for use in microfilm systems or the like. The system is operable during the recording of an image of a document on film to simultaneously record numbers and/or other indicia on the film which may relate to the document. It is usable during the simultaneous recording of images of both sides of a document, provides accurate and clear recording of indica and is readily controlled.
2. Background of the Prior Art
Prior art film writing systems have been used to identify documents which have been transferred to microfilm. Alpha or numeric characters are photographed by a microfilm camera and placed alongside microfilm photographs to make document identification easier.
In prior art microfilm identification systems, an identification code made of generated alpha or numeric characters is directed to the lens of a microfilm camera through the use of a relay lens. Typically, a liquid crystal display is used to generate the identification code. When characters are generated on the liquid crystal display, some segments of the display are turned on and others are turned off. On one side of the display sits a light which illuminates the backside of the display. Since turned-on segments of the liquid crystal display are opaque to the light and turned-off segments allow light to pass through, a visible image is created which can then be photographed. This image is directed and focused by a relay lens to the lens of a microfilm camera. The relay lens must be positioned accurately within such a microfilm identification system to insure proper focusing of the LCD image and to insure the image is directed to the proper location on the microfilm.